Month: March 2014

Splitting a CSV file into a bunch of columns

awk -F, '{for(i=1;i<=NF;i++){print $i > "sample"i".csv"}}' yourfile.csv

Does what is says on the tin. Splits your CSV file into a bunch of files, one for each column of the original files. Found here.

I’m using this to pull single channels out of a 60 channel file full of recorded neuron voltages, which I’m then throwing through a little filter test program that I whipped up using this filter library. My main goal is getting rid of 60Hz line noise, but the fluorescent bulbs in the room apparently also make noise at 180Hz and 300Hz.

I waste time to not waste time

I’m using a web server on my local machine plus an edited /etc/hosts file to serve up a page that reminds me to get back to work when I should be getting back to work, rather than, say, reading facebook. Yes, I can get around this by clearing my hosts file, but that makes it work to get to the blocked sites, and if I’m going to be doing work, it’s not time-wasting is it?

The hosts file looks like this:

ams@robot-lab7:~/weblock$ cat /etc/hosts localhost.localdomain localhost
#I elided a couple of lines here

# The following lines are desirable for IPv6 capable hosts
::1 localhost ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
ff02::3 ip6-allhosts

That takes care of redirecting a lot of pages to localhost, rather than their real IP addresses. On my computer, I have a little web server, which is launched with the command
sudo webfsd -p 80 -f index.htm -u ams -r /home/ams/weblock/

Webfs, and it’s daemon part webfsd, is a static-file-only http server. In this invocation, it runs as my user after binding to port 80 as root, and serves the file index.htm out of the directory /home/ams/weblock. That file is a very simple HTML file:

<div style=”display: table; height: 100%; width: 100%; background: #fff; _position: relative; overflow: hidden;”>
<div style=”_position: absolute; _top: 50%; display: table-cell; vertical-align: middle; text-align: center;”>
<h1>What should you be doing?</h1>

It just shows the text “What should you be doing?” in the middle of the page. This is also interesting because it shows how to center HTML content in the middle of the page, at least for small content. I’m not sure how well this works with larger or more complex content.